As methods for granulation of food additives (sweeteners, flavoring materials, preservatives, dietary supplements, acidulants, etc.) and the like, there have been known extrusion granulation, fluidized granulation, compression molding, mixing-stirring granulation, melt cooling granulation, spray drying granulation and the like. In any granulation method, water and fats and oils are often used in addition to excipients.
Among them, in the case of granulation of food additives and the like, generally, a granulated product is obtained by humidifying a mixture of a food additive and an excipient such as a saccharide or the like with an aqueous solution of a binder such as starch, gelatin or the like and extruding from a die screen to granulate the mixture, or keeping the mixture suspended in air, while spraying an aqueous solution of a binder to granulate the mixture, and then drying the resulting granules with heating.
In these conventional methods, certain food additives are decomposed by heat during the drying step, which results in loss of the food additives. Further, due to vaporization of water, disadvantages in energy and cost are predicted.
Melt cooling granulation method is considered to be a best granulation method for materials which are decomposed in the presence of water or during drying because heat molten properties or press molten properties of excipients are utilized in the method. However, in many cases, melt cooling granulation method employs a hardened oil, a saccharide or the like as an excipient to carry out granulation and there is a problem that a granulated product obtained by using a hardened oil is insoluble in water. And, when granulation is carried out by using a saccharide, a melting temperature should be considerably high depending upon a particular saccharide used. Due to this, the food additives are decomposed, which results in loss of the additives, and further a problem such as coloring of the granulated product obtained is resulted.